Okay I figured it out. I thought Opera shipped with Flash just like Google Chrome but apparently not, so I had to go to https://get.adobe.com/flashplayer/ and download flash from there then install. After restarting Opera GX, Flash now works.
Seriously, push out an update quickly. Change the sorting algorithms and get rid of this bullshit. I play games to keep my mind off suicidal depression, not to make it worse. I don't need to see degeneracy, either.